Vulcanizing caoutchouc



lid

u-n-m STATES ATENT OFFICE.

CLAYTON w. Bnnrom) ANn'noBERT L. SIBLEY, or AKRON, onrro, assmnons T0 irna eoon nan man & RUBBER COMPANY, or. AKRON, 01110, A conronarron or vvncanrzme CAOU'IGHOUC.

No Drawing. I A

Vulcariizin'g Caoutchouc", ofwhichthe following is a specification.

The present invention relates to the art of vulcanizing caoutchoucand will be 'fully understood from the following specification The organic substance pa'ranitroso-di methyl-aniline has heretofore been emloyed as an accelerator in the'proce'ss'of vu canizing caoutchouc,'- e have discovered that this substance .in neutral solutions both; aqueous and non-aqueous, and in fact in any. suitable inactive organic solvent, such-1 as benzol C H "will react-quantitatively with by rogen sulphide to produce acom ound having. strong basic properties" and orminga valuable accelerator for vulcanization. .7

and the fact thatit contains a basic nitrogen group is evidenced. by its violent reaction 'withfcarbon bisulphide to produce la sub; stituted thiourea with a corre's ending loss of H S;. '*The amido compoun s'in general react rather slowly with carbon bisulphide. and the correspondin thioureasare usually produced commercia y by the'aid of, catalysts suchas sulphur pyridine, etc., which aid in removal of the ll s from the reaction. With a strong base such as piperidine, how ever, reaction with CS proceeds with extreme violence without the necessity-for any The base which weproduce appears to "cor respond to v the order of piperidineg, I far asits strong basicity isconcerned', shown b itsviolent reactionf with carbon bisulphi e- (CS with accom anyingvio lent evolution ofhydro'gen sulp ide and the heatin up of the reaction mixture.

We ave found that this base the reaction product of hydrogen sulphlde a and paranit'roso-dimethyl-aniline' is a 'val uableaccelerator, being particularly superior in this use to aran t'roso-dimethyliaml1ne itself, in that it is more stable in storage and is not as active a poison within the limitsof its use in the vulcanization of rubber constituting 1 Application filed August 12,1s1sf Serial No. 249,579.

In the practice of our invention we may proceed as follows: i

Example: One molecular "weight (150 parts) of paranitroso-dimethyl-aniline is dissolved in benzol or in water, and hydrogen vsulphide is passed into and "dissolved by the solution at any temperature up to the boiling pointof the solvent until no more will react. The dimethyl-ani ine disappears and there is produced a base which is dark in color and often of a tarry consistency On evaporation of the solvent and of the water formed in the reen color of the paranitroso reaction the wei ht of the paranitroso-dimethyl-aniline w1ll be found to have increased by an amount substantially equivalent to the difference between the molecular weight of hydrogen sulphideand that of water, apparently corresponding to the following equation: I cH N o H 'N0+ 2 The strongbasic properties ofjthe productf We have therefore found that under cer tain conditions the reaction proceeds as shown in the foregoing, i;e.-, 1 molecule paranitroso-dimethyl-aniline plus. 1 molecule hydrogen sulphide'givesl molecule of water plus 1 molecule of .a strong base.

By var ing the conditions of the reaction, I

' entirely ifierent results may be obtained as fbllowsg-l molecule of paranitroso-dimethyl-aniline plus two molecules of hydrogen sulphidegives 1 molecule of water plus two atoms of sulphur plus 1 molecule of a base which is probably para amide t stron dimet yl-aniline. catalysts, the reactionimixture becoming hot? 'J'wH LmQHF M s iia .ui fiisi of theabove examples, para- Y amido-dimethyl-aniline' is apparently not :f rmed b1- 1tin .itsf'place a compoun 1 1 inf constitution-andbasic roperties but apparentlyi eentaiz'iinga su phuratom in its structural-makeup. a

We have discovered therefore a new method of .preparin a base bythe reaction of less than two mo s of hydrogen sulphide on one mol of 'paranitroso-dimethyl-aniline A small and it's use as an accelerator. percentage of this base is added to caoutchouc (for example in the proportion of one-half to two per cent of the weight of the latter) and the whole then heated with a vulcanizing agent in the usual way to effect vulcanization. The base exerts a marked beneficial influence on the vulcanizing process, giving a'vulcanized product of superior quality.

Similar products, likewise useful for the vulcanization of caoutchouc may be produced by the reaction of hydrogen sulphide on other paranitroso bodies, such, for example, as paranitroso-phenol.

VVhilewe have in the foregoing described in detail one manner of carrying out our invention, together withour theories as to the nature of the reactions which take place, and the characteristics of the products, it will be understood that this is illustrative only, and for the purpose of making the invention more clear, and that the invention is not limited to the procedure mentioned, nor dependent upon the accuracy of the theories which we have advanced, except in so far'as such limitations are included within the terms of the accompanying claims, in which it is our intention to claim all novelty inherent in our invention as broadly as I is ermissible in view of the prior art.

hat we claim is: v

1. The process which consists in incorporating a small percentage of the reaction products of paranitroso dimethylaniline with less than two molecules of hydrogen sulfide into a caoutchouc mixture and heating with a vulcanizing agent.

2. The process which consists in incorporating a small percentage of the reaction products of aranitroso dimethylaniline with one molecu e of hydro e n sulfide into a caoutchouc mixture and eating with a vulcanizing agent.

3. The process which consists in incorporating a small percentage of a reaction products of paranitroso dimeth laxniline with hydrogen sulfide having an u timate composition correspondin approximately to the formula (CH .O' H (S)NH into a caoutchouc mixture, and heating with avulcanizing agent.

4. The process which consists in incorporating into a rubber mix a small percentage of the reaction products of one mol of a paranitroso body with less than 2 mols of hydrogen sulphide and heating with a vulcanizing agent.

5. The process which consists in incorporating into a rubber mix a small percentage of the reaction products of one mol. of a paranitroso body with one mol of hydrogen sulphide and heating with a vulcanizing agent.

6. The process which consists in incorporating a small percentage of the reaction products of paranitroso-dimethyl-aniline in solution in an inactive neutral solvent with hydrogen sulphide into acaoutchouc mixture and heating with a vulcanizing agent.

7 The process which consists in incorporating into a caoutchouc mixture the reaction products of one mol of paranitro-dimethylaniline in solution in an inactive neutral solvent with less than two mols of hydrogen sulphide and heating with a vulcanizlng agent.

8. The process which consists in incorporating into a caoutchouc mixture the reaction products of one mol of paranitro-dimethylaniline in solution in an inactive neutral solvent with one mol of hydrogen sulphide and heating with a vulcanizing agent.

CLAYTON wv. BEDFORD. ROBERT L. SIBLEY. 

